Sometimes your first day of work also serves as a declaration. Perhaps your boss hired you to make changes to the existing work culture or bring a fresh perspective and new ideas. Unfortunately, offices can be terribly insular places that resist change and deeply distrust outsiders. So even if you have the best ideas in the world -- even if the higher-ups brought you on board specifically to shake things up -- keep them to yourself on the first day.
The best way to win people's trust is simply by listening to them [source: Vogt]. Show respect for their opinions and seek feedback on your ideas before presenting them as the new reality [source: CareerBuilder]. When in doubt, bring doughnuts.